Hand carry luggage to ride on Yufuin no mori

I have a hand luggage with me when I visit to Kyushu. Unfortunately I will only still 1 night in Yufu, 1 in Beppu, 1 in Aso and 1 in Kumamoto. I wonder if I can bring my hand luggage with me throughout the trip. Is the Yufuin train allows me to do so?

https://www.jrkyushu.co.jp/english/pdf/oversized_baggage.pdf?_gl=1*p5g.....

That link has information on bag size measurement and whether you need to reserve or not

These oversized baggage rules apply only to selected shinkansen trains, and not to the Yufuin no mori. Brininging a nromal sized bag onto the Yufuin no mori is no problem.

The official max. limit is 250cm if you add up height, lenght and depth, but to make yourself and the people areound you a favour, keep it down to a regular size.